Minimum Effective Intrathecal Dose of Local Anaesthetic With Fentanyl for Fractured Neck of Femur(Dose Finding Study).

Determination of the Initial Minimum Effective Dose of 0.5% Bupivacaine With 20mcg of Fentanyl Via a Spinal Catheter for Operative Fixation of Fractured Neck of Femur.

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01922622

Enrollment

Registered

2013-08-14

Start date

2013-07-31

Completion date

2014-06-30

Last updated

2015-02-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Minimum Effective Dose of Local Anaesthetic With Fentanyl

Keywords

minimum effective dose of local anaesthetic, spinal catheter, fractured neck of femur, a step up, step down methodology

Brief summary

Fractured neck of femur (FNF) is a common cause of admission to hospital in elderly patients with multiple comorbidities. Anaesthetic management of this patient group is extremely challenging.Neuraxial anaesthesia with minimum doses of local anaesthetic agents administered via a spinal catheter leads to better cardiovascular stability.The minimum dose of local anaesthetic with intrathecal fentanyl was not established yet.We propose to study and determine the initial minimum local anaesthetic dose (MLAD) of 0.5% bupivacaine with 20 mcg of fentanyl administered via a spinal catheter to achieve a sensory block up to T10 for the operative fixation of FNF.We will use a previously well established Dixon and Massey up-and-down method to calculate initial MLAD in this prospective, observational trial. Objectives: We would like to determine the initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl administered via a spinal catheter required to achieve a sensory block up to T10 on the side of FNF. Outcomes Primary outcome: 1. Initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl required for a sensory block up to T10 on the side of FNF. Secondary outcomes: 2. Total dose of 0.5% bupivacaine with 20mcg of fentanyl required for the operative fixation of fractured neck of femur. 3. The effect on haemodynamic variables (blood pressure, heart rate). 4. Incidence of side effects 5. The length of postoperative analgesia (the time from the last dose of local anaesthetic administered intrathecally to VAS\>3). 6. The time to first rescue analgesic requirement Study Design Prospective, observational trial. Study Size Based on the previously well established Dixon and Massey up-and-down method(10), we will recruit patients until a successful spinal block has been achieved in six consecutive patients who received a specific dose. This is the requirement to calculate the initial MLAD.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

60 Years to No maximum

Healthy volunteers

Inclusion criteria

* fractured neck of femur * Above 60 years * American Society of Anesthetists(ASA) I to III

Exclusion criteria

* Patient refusal * Outside Age Range * Contraindications to spinal anaesthesia * Head injury or other associated injuries * Loss of consciousness and signs of acute coronary syndrome * Mini-Mental Score \< 25 (Appendix 2) * Allergy to bupivacaine, lignocaine or fentanyl

Design outcomes

Primary

Measure	Time frame	Description
Initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl required for a sensory block up to T10 on the side of FNF	15min	A blinded observer will assess the dermatome level of sensory blockade with an ice-cold test (ethyl-chloride spray) bilaterally after the injection of the local anaesthetic. Block assessment will be performed every 5min up to 15 min after completion of the initial intrathecal injection. Sensory block up to T10=positive result Sensory block below T10=negative result.

Secondary

Measure	Time frame	Description
Total dose of 0.5% bupivacaine with 20mcg of fentanyl required for the operative fixation of fractured neck of femur	Duration of surgery.	Initial dose and all top ups will be recorded and analysed in conjunction with the length of surgery and surgical procedure used to fix FNF.
The effect on haemodynamic variables (blood pressure, heart rate).	Duration of surgery.	Noninvasive automated blood pressure and heart rate measurements will be recorded before the spinal anaesthesia (baseline) and every three minutes after the end of local anesthetic injection until the end of surgery.Hypotension is defined as a decrease of more than 20% from the baseline systolic arterial blood pressure (SAP). Severe hypotension is defined as a decrease in SAP more than 30% of baseline value. Hypotension will be treated with IV boluses of ephedrine 6 mg if the heart rate is below 60/minutes or phenylephrine 100 mcg if the heart rate is above 60/minutes.The number of hypotensive episodes, a total amount of vasopressor administered, and the i.v. fluid infused will be recorded as well as duration of anaesthesia.

Other

Measure	Time frame	Description
Incidence of side effects.	24-48 hours	Patients will be interviewed 24-48 hours after surgery regarding side effects of spinal anaesthesia (headache, pruritus,postoperative nausea and vomiting,urinary retention,neurological deficit)
The length of postoperative analgesia (the time from the last dose of local anaesthetic administered intrathecally to VAS>3).	1-2 hours	The time from the last top up of local anaesthetic to VAS \>3 and to the first dose of break through analgesia will be recorded.

Countries

Ireland

Outcome results